Exemplary embodiments of the disclosure generally relate to an aircraft, and more particularly, to structural health monitoring of an airframe of an aircraft.
Because all structures in use are exposed to repetitive loading, environmental conditions and other external threats, such structures should be monitored for structural integrity and health condition to prolong their life and/or to maintain safety. Numerous systems and methods have been used to identify faults and/or damage of structures, including visual inspection and non-destructive techniques such as eddy current scanning, ultrasonic transmission, acoustic emission, and X-ray inspection. However, these conventional methods require at least temporary removal of structures from service for inspection.
New manufacturing methods are being developed to optimize the assembly of composite based airframe structures with the goal of removing fastened joints. Assembly of composite structures without fasteners improves load transfer efficiency, reduces weight and simplifies manufacturing processes. Among the technical approaches being developed is the use of 3D woven textile structures to serve as joining members in an adhesive interface. One such application is the “pi” joint which has a base that adheres to one member of the joint and a clevis that adheres to the adjoining member.
New diagnostic techniques for in-situ structural health monitoring have been developed. Typically, these new techniques utilize non-embedded, externally mounted sensor systems. However, these new systems have drawbacks, such as susceptibility to sensor system damage, and may not provide effective methods for evaluating structural health. Further, implementing structural health monitoring systems on existing structures can be difficult due to challenges with integration.
There is therefore a need to develop a mechanism for integrating structural monitoring capability into the structural members of a composite airframe so that structural monitoring may be performed without removing the aircraft from active service.